1. Technical Field of the Invention
The invention concerns an apparatus and method for generating a digital representation of the contour of surfaces of the human foot and using this information to manufacture custom shoes and shoe inserts or select a proper fitting shoe or insert from inventory.
2. Description of the Related Art
It has long been recognized that a digital representation of a surface of the human foot may be obtained by sensing the positions of an array of resiliently biased gauging pins that make an impression of the foot as it is pressed against the pins. The relative displacement of each pin is measured by mechanisms that generate digital signals which define a contour or profile of the surface of the foot. Such systems have typically used a separate sensor to measure the displacement of each pin after it is engaged with the foot. It has been suggested that the data collected by such systems can be used to manufacture custom shoes or shoe inserts that match the contour of the foot or select shoes or inserts from inventory. The digital data has also been used to provide computer display images of the surface contour of the underside of the foot.
In one known system, magnetic pins are raised up to meet the underside of the foot and are resiliently supported by a flexible air-biased diaphragm so that they are displaced as the foot presses against them. The pins are locked in position after the foot has formed an impression by displacing them. A stepping motor incrementally moves hall-effect scanning elements which sense the displaced positions of the magnetic pins. The position of each pin is then determined by an analytical process that requires averaging arrays of data obtained for the incremental vertical steps of the scanning elements.
More recently, a foot scanner has used cameras to detect the displacement of an array of gauge pins that are locked in place to retain the impression of the foot. The images are analyzed by computer software in order to generate a digital representation of the surface of the foot.
Capacitive sensors have also been employed to detect the displacement of gauging pins. It has also been suggested that an image of the underside of the foot can be obtained by scanning the bottom of the foot with light.
The methods of these known systems tend to complicate the process for obtaining contour information. Such systems are also quite expensive in view of the complex machinery and computer analysis required to obtain a contour.
It would therefore be desirable to provide a contour sensing apparatus that does not require individual position sensors to detect the final deflected positions of an array of pins. It would also be advantageous to provide a system that employs relatively inexpensive, reliable and simple mechanisms and procedures for obtaining contour information. It would also be advantageous to provide a system with relatively simple computational requirements, for example as would be employed by an inexpensive microcontroller.
These and other advantages are achieved by the system of the invention which employs gauging or sensing pins in a relatively simple and effective manner. The system of the invention can detect the contour of the foot or any other object quickly and with minimal expense for hardware and software.
The invention concerns a method and apparatus for measuring the contour of any object, including the human foot. The system of the invention employs gauging or sensing pins that are resiliently supported in a holder and moved to engage the surface of an object. A relative displacement for each pin is detected at the time the pin initially contacts the surface. In operation, as the surface touches and actuates a pin, the relative displacement of the actuated pin is detected and the displacement value at that point is stored. Sensing of these displacement values continues until relative displacements of all actuated pins have been stored. These stored values define the contour of the surface.
The digital contour information obtained from the system of the invention can be used to manufacture or select shoes and inserts for shoes if the sensed object is the human foot. Shoe size, shoe purchases and other demographic information for the purchaser of shoes can be collected in a database and used to assist individuals in selecting shoes. Other favorable results can be achieved if the surfaces of other objects are sensed.